Film-advancing means for cinematographic view-taking apparatus



A. L. v. c. DEBRIE 1,789,222 Film ADVANCING MEANS FOR CINEMATOGRAPHIC VIEW TAKING ltfPAR'IUS I me; Dec. zo. 1929 Jan. 13,1931

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v.dl -|.l||.|-|| -...mwl l m5 l-- 2 v o ,W 2 .M x f f y/ m lso resented Jan, 13, 1931 UNITED STATES PATENT OFFICE ANDR LON VICTOR CLMENT DRBRIE, F PARIS, FRANCE FILM-ADVANCING MEANS FOR CINEMATOGRA-PHIC VIEW-TAKING APPARATUS Application led December 20, 1929, Serial No. 415,581, and in France November 18, 1929.

In most cinematographic view taking apparatuses the film is generaly advanced with a step by step motion through successive lengths equal to the length of one picture. The successive advance motions are separated by the exposure periods of the different parts of the film corresponding each to one picture. The advance is controlled by means' of claws engaging the film perforations during the advance period of the iilm, said claws' being re tracted-during the exposure periods before engaging those film perforations spaced behind the perforations formerly engaged by a length equal to the length of a picture. In such devices, itis of advantage to reduce as. much as possible the motion period of the film in order to increase the exposure period.

My invention has for its object a device for achieving this result. It comprises a lever freely rocking round a first spindle adapted to rock freely round a second stationary horizontal spindle perpendicular to the first spindle; one of the lever arms controls the movement of the claw or claws sliding in a vertical guide and held parallel to the stationary spindle. The other lever arm is connected with an eccentric crank pin on the control plate the axis of which is lparallel to the stationary pivot spindle. his connection is such that the claw controlling lever arm comes nearer the film when the crank pin on the control plate comes nearer the pivoting spindle and passes away from the spindle during the remainder of the travel of the crank pin.

I have shown by way of example on accompanying drawings a form of execution of my invention. y

Fig. 1 is a horizontal sectional view of the device along line ABCDEF of Fig. 2.

Fig. 2 is a horizontal sectional view of the device along line GHIJ of Fig. 1.

Fig. 3 is a vertical sectional view thereof along line KL of Fig. 2.

The film-advancing pin 1 is disposed so as to be capable of sliding longitudinally inside a tube 2 an extension 4 of which forms a bearing'for the cylindrical enlargement or collar 5 formed on the pin. The bearing 4 is -secured to a plate3 sliding in the vertical guides 6, v7 secured to the casing 8. The bearing 4 is adapted to move through a vertical comparatively high aperture 9, provided in the casing 8. The tube 2 has apertures 10,

11 'adapted to allow the stud 12 raised on the pin to engage the slots 13, 14 provided in each of the forward arms 15 of the lever 16 This stud 12 slides freely without any play in the slots -11 which serve vto guide it. The lever 16 is pivotally mounted on the pivot or spindle 17 carried on the spindley or socket 19 pivotally mounted in the bearing The arm of lever 16 o posed to the fork l is pivotally secured to the eccentric crank pin 2O forming a socket borne by the control plate 21 as described hereinafter. The crank pin has an extension 22 adapted to pivot reely in the sleeve 23 secured to the plate 21. It has a recessed part 24 wherein the lever 16 is adapted to slide and carries a projection 25 passing through a cam-shaped groove 26 provided in the lever. `The shape of the camshaped groove is that shown on the draw- The working of the device is as follows:

upposing the plate 21 rotates in the direction of the arrow f, the axis of the crank pin will describe the circular path C.

The extreme positions of the longitudinal -axis of the lever 16`when rocking correspond to the tangents thereto O T and O T passing through its axis of oscillation. The vertical motion of the advancing pin is thus limited by the intersections SS of the said tangents OT OT with the axis U U of the film perforations. Thus when the crank pin is between T and T, the projection 25 will remain in the part VX of thecam and consequently the fork 15 will come nearer the film so that the pin engages a perforation( When the crank pin nears the point T` for'instance, the projection 25 engages the sloping part XY of the cam-shaped groove whereby the forked end 15 of the rocking lever will be moved away from the film so as to disengage; the pin therefrom. After this, in the part beyond lT and before T', the projection 25 will engage the part Y orresponds to the return stroke of pin; when the axis of the crank pin arrives near point\ T, the projection returns to the part Y X of the groove so that the pin reengages a perforation. It is thus apparent that the film-advancing period corresponds to the rotation of the crank pin inside the angle T OT whereas the pin -return period corresponds to a substantially larger rotation QW-TOT. If it is supposed that the plate i paratus, film-advancing means comprising a pin adapted to engage the film perforations, a pivot parallel to said pin a spindle adapted to pivot round said pivot in a plane perpendicular thereto, a lever adapted to rock freely round said spindle andone end of whichl controls the movements of the pin perpendicular and parallel to the film surface, means for keeping the pin parallel with the abovementioued stationary pivot, a rotatable control plate the axis of which is substantially parallel to the pin and to 'the pivot, a crank pin eccentrically and rotatably secured to saidplate and guiding means whereby said crank pin controls the free end of the lever and makes said end'recede away from the film plane during the shorter of the ltwo circular travels of the crank pin bringing same fromoneto the other of the two positions where the lever is tangent to the path of said crank pin.

2. In a cinematographic view taking'apparatus, film-advancing. means comprising a pin adapted to engage the film perforations, a pivot parallel to said pin, a spindle adapted to pivot round said pivot in a plane perpendicular thereto a lever adapted t0A rock freely round said spindle and one end of which controls the movements of the pin perpendicular and parallel to the film surface, a longitudinal cam-shaped groove-provided inthe other end of the lever and the inner end of which is nearer the film plane, means for keeping the pin parallel with the abovementioned stationary pivot, a rotatable control plate the axis of which is substantially parallel to the pin and to the pivot, a crank l pin eccentrically and rotatably secured to said plate and a projection on the crank pin adapted to engage the groove in the lever..

3. In a cinematographic view taking apparatus, film-'advancing means comprising a pin adapted to engage the lm 4perforations, a pivot parallel to said pin a spindle adaptedto pivot round said pivot in a plane perpendicular thereto, a lever adapted to rock freely round said spindle, a fork formed byone end of the lever, a sleeve wherein the pin is slidably carried guided between thev fork arms whereby the forked end of the lever controls the movements ofthe pin perpendicular to the film surface, means for eeping the pin parallel with the abovementioned stationary pivot,'a rotatable control plate the axis of which is substantially par-- one to the other of the two positions where the lever is tangent to the path of said crank pin.

4. In a cinematographic view taking apparatus, film-advancing means comprising a pin adapted to engage the film 'perforations,v a

pivot parallel to said pin, a spindle adapted to pivot round said pivot in a plane perpendicular thereto, a lever adapted to rock freely round said spindle, a fork formed by one end of the lever and provided with a longitudinal slot, a sleeve wherein 'the pin is slidably carried and guided in its movements parallel to the film between the fork arms,

the fork, means for keeping the pin parallel with the abovementioned stationary pivot, a rotatable control plate they axis of which is substantially parallel to the pin andto the pivot, a crank pin eccentrically and rotatably secured to said plate and guiding means whereby said crank pin controls the free end of the lever and makes said end recede away from the film plane during the shorter of the twocircular travels of the crank pin bringing same from one to the other of the two positions where the lever is tangent to the path of said crank pin.

lIn testimony whereof I have signed my name to this specification.

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a a projection on the pin engaging the slot in 

